Constructional material



March 18, 1930. A. c. FISCHER CONSTRUCTIONAL MATERIAL Original Filed May 10, 1922 Patented Mar. 18, 1939 AT FFICE ALBERT C. FISCHER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE PHILIZ? CAREY MANU- FACTURING COMPANY, A. CORPORATION OF OHIO GONSTRUQTIONAL MATERIAL Original application filed May 10, 1922, Serial No. 559,908. Patent No. 1,680,144. Divided and this application filed October 16, 1925, Serial No. 62,908. Renewed April 20, 1929.

This application is a divsion of my application Serial No. 559,908, filed May 10, 1922, and which matured into Patent No. 1,680,144, August 7, 1928.

The invention relates to improvement in constructional material and to the method of the construction of same, as more fully described hereinafter and particularly pointed out in the claims, and particularly pertains to reinforced asphaltic slabs, such as expansion joints.

Heretofore it has been the practice in the manufacture of expansion joints to impregnate felt strips and build them into layers,

or reinforce asphalt mixture with saturated felt sides, also the prior art teaches fibrous matter mixed with tar, pitch or bituminous substances. w

In all the above the mixture have been cffected with heated liquid or semi-liquid ma terials, so that the contents are saturated thoroughly and the mass becomes a saturated mixture and consequently contains few if any air cells. On the other hand the rigidity of the fibre for structural purposes is destroyed, and it does not act as a separate structural skeleton for the surrounding mass, Consequently, in warm weather expansion joints made by the old method become limp and flabby, because of their lack of struc tural framework acting independently of the surrounding mass.

By my method of mixing cellular granules, unsaturated, fibrous matter, and other like substances, such as excelsior out in small lengths, stiff, fibrous flax, etc, and incorpo= rating same in the mixture while the bituminous matrix is plastic, and therefore lack= ing in penetration power, I am able to efiect a structural skeleton within the matrix which. an ports the matrix in warmer temperatures. l am also able to effect cells or pockets in the structure which allow for compressibility, and because of the unsaturated materials or cellular granules the walls of the bituminous matrix cannot adhere together upon compres sion and, will, therefore, respond to expansion u on release of the compression. Certain v fi res, such as, mineral wool, cause the walls 5 of the matrix to harden immediately where in contact, which also makes for a stronger structure, so that there is a structural strengthening both by chemical action and by preserved rigidity in the fibrous matter which is unsaturated;

I have eilected through this method the possibility of efiecting several types of structure, namely, a bituminous and fibrous mixture eilecting a chemical change, strengthening the structure, a bituminous and fibrous mixture strengthening the structure due to unsaturated fibrous matter; a bituminous cellular structure containing within the cells granules, such as, cork, which in itself is cellular, screened mineral wool granules, which are also cellular, treated wool granules in a cellular state, and any other like form of cellular or fibrous matted matter, such as, excelsior, digested strawg flax, etc. in an unsaturated state, or at least not solidly saturated, due to penetration of the bituminous matrix.

In the drawing the figure represents an expansion joint containing bituminous material a and mineral wool fibre b, the chemical action of the fibres havin hardened and therefore strengthened the liituminous wall immediately about them, the remaining portions ofthe bitumen of which the strjp is composed being softer than the hardened portions in contact with the mineral wool.

This division relates to a mixture of mineral Wool, thru a mixing process, with bituminous material while the material is in a Warm, plastic state, and utilized for this purpose are mixing devices readily procured upon the market. The proportions will be determined by the stifi'ness of the material required, and by incorporating mineral wool in the bituminous material in the state outlined, it will be distributed thru the mixture. It is not advisable to mix the material too long, just sufi'icient to have the fibrous material covered over, and then the mass formed into slabs or sheets suitable for expansion material.

As clearly shown in the figure of the drawing, by mixing of the mineral wool into the bituminous matrix for a relatively short time the fibres of the mineral wool are pulled-out so as to form a structural skeleton of tenuous 100 fibres within the matrix, which immediately harden where they contact with the bituminous matrix, thereby adding considerable rigidity and strength to the strip. Particular attention is drawn to the fact that the mixing is not prolonged, for if such were the essential to an expansion joint.

Thus it will be found that this mixture for forming an expansion joint has a tree-like or skeletonized, reinforcing structure incorporated init, consisting of mineral wool fibres, and because of the chemical action of the mineraliwool upon the asphalt that part of the asphalt which comes in contact with the mineral wool will be hardened, thus forming a body of bituminous material having facelike hardened pockets or casings over mineral wool fibres distributed thru its mass.

Mineral wool is ordinarily thought of as being chemically inert since itis supposed to be a mixture of fused silicates. The commercial product, however, is far from a pure glass and contains both acid and water soluble materials. It is made from a dolomite rock which consists mostly of magnesia and calcium carbonates and contains only limited quantities of siliceous material. At a temperature of 3000 F. these carbonates are decomposed to oxides, and, unless there is sufiicient silicate present to combine with the latter, theywill remain as free bases more or less mechanically occluded. This has been fairly well established by an examination of the water and acid soluble materials. The former has a definitely alkaline reaction and since the amount of alkali present in the rock is very small, this material is probably calcium or magnesia hydrate. The addition of acid liberates hydrogen sulphide from small amounts of iron and calcium sulphide which are present.

In addition, a large amount of the acid is neutralized without any evolution of gas thus indicating the presence of free bases. The action-of acidis very noticeable when the treated material is placed under a microscope. The surfaces of the glass fibres are irregular and pitted and have numerous fine particles adhering to them. The latter are a part of the original rock material which is insoluble in acid and has been mechanically held in a fused mass.

In a material having a composition as described above, two kinds of hardening can be brought about when in contact with asphalt.

l, The physical hardening will take place in the asphalt adjacent to the fibres due to the mineral matter present on the surface which becomes incorporated in the surface layer of asphalt. i

2. The chemical hardening will result by the action of the sulphides on the asphalt layer adjacent to the mineral wool fibres depending somewhat on the quantity of sulphides present, the temperature, and the length of time they are in contact. In general, the extent to which the hardening of the. asphalt will take place is dependent on the individual samples of mineral wool and the nature of the mixing whereby they are brought in contact with each other. All samples of mineral wool, however, are sufliciently impure to bring about some eifect of this nature on almost any consistency of asphaltic material which does not flow at ordinary temperatures.

. An expansion joint as outlined above will have the following properties:

It will resist heat penetration.

It will contain a skeleton structure to give it strength before installation in the crevice.

It will be subject to considerable compression and will re-expand with much less resistence.

It will compress without elongation.

I claim:

1. The method of preparing expansion joint material consisting in distributing a measured quantity of mineral wool through a measured quantity of bituminous matter while the bituminous matter is in a warm plastic state, and mixing the ingredients together for a time just suflicient to coat the mineral wool fibers with the bituminous matter, thereby causing the mineral wool to form a hardened skeletonized structure within th bituminous matter.

2. Expansion joint comprising a strip of bituminous material having mlneral wool distributed through the same, said mineral wool being unsaturated to provide pockets through thebituminous material, the walls of said pockets being hardened by a constituent in said mineral wool.

3. An expansion joint composed of bituminous material and mineral wool, the mineral wool bein unsaturated and arranged to form a tree-like or skeletonized structure within the bituminous mass,'the walls of the bituminous material about the structure being hardened.

memes bituminous material, the bituminous material contiguous the reinforcing medium being hardened, the remaining bituminous material being unhardened.

5. A preformed expansion joint composed of bituminous material and an unsaturated fibrous material incorporated in the bituminous material to provide hardened areas therein in the form of a skeletonized reinforcing structure.

6. A preformed expansion joint composed of bituminous material having hardened areas therein formed as a skeletonized, internal reinforcement, certain other portions of the bituminous material being relatively softer.

7. A preformed expansion joint formed of bituminousmaterial and a branchlike formation of mineral Wool incorporated therein to provide a relatively rigid reenforoe to support the bituminous material.

8. The method of preparing expansion joint material consisting in mixing mineral Wool in bituminous material when in a warm plastic state, and for a time just sufficient to have the fibrous material covered over and the fibres of the mineral wool pulled out into branched, tenuous formation to form an internal skeleton-like structure within the bitumen, whereby the bitumen in contact with the mineral wool will harden.

9. preformed, boardlike expansion joint, comprising a compressible bituminous binder, otherwise incapable of holding its form, and reenforcing means therefor consisting of an internal skeletonized structure of mineral wool of substantial length, which mineral wool is unpenetrated by'the bituminous material.

10. The method of preparing constructional material consisting in distributing a measured quantity of mineral wool through a measured quantity of bituminous matter while the bituminous matter is in a warm plastic state, and mixing the ingredients together for a time just suficient to coat the mineral wool fibers with the bituminous matter, thereby causing the mineral wool to form a hardened skeletonized structure within'the bituminous matter.

11. A constructional unit comprising a strip of bituminous material having mineral wool distributed through the same, said mineral wool being unsaturated to form pockets through the bituminous material, the walls of said pockets being hardened by a constituent in said mineral wool.

12. A constructional slab composed of bituminous material and mineral wool, the mineral wool being unsaturated and arranged to form a tree-like 0r skeletonized structure within the bituminous mass, the walls of the bituminous material about the structure being hardened.

13. A preformed constructional unit composed of bituminous material and an unsaturated structural rein-forcing medium within the bituminous material, the bituminous materi'al' contiguous the reinforcing medium being hardened, the remaining bituminous material being unhardened.

14. A preformed constructional unit composed of bituminous material and an unsaturated fibrous material incorporated in the bituminous material to provide hardened areas therein in the form of a skeletonized reinforcing structure.

15. A preformed constructional unit composed of bituminous material having hardened areas therein formed as a skeletonized,

internal reinforcement, certain other portions of the bituminous material being relatively softer.

16. A preformed constructional unit formed of bituminous material and a branchlike formation of mineral wool incorporated therein to provide a relatively rigid reenforce to support the bituminous material.

17 The method of preparing constructional material consisting in mixing mineral wool in bituminous material when in a warm plastic state, and for a time just suflicient to have the fibrous material covered over and the fibers of the mineral wool pulled out into branched, tenuous formation to form an in.-

ternal skeleton-like structure within the bitu-- men, whereby the bitumen in contact with the mineral wool will harden.

18. A preformed, board-like constructional unit, comprising a compressible bituminous 

